Ophthalmoscope.



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OPHTHALMOSGOPB. I APPLIoATIoN FILED nomia, 190s.

NO MODEL.

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UNITED vSTATES PatentedAprl 26, 1904.

PATENT OFFICE, p

CHARLES MCCORMICK, OF CHICAGO, ILLINOIS.'

OPHTHALMOSCOPE.

SPECIFICATION forming part of LettersPatent No. 758,092, dated yAprilZG, 194. Application led Nvember 13, 1908. Seriai Nu. 180,992. (No modelli.'l l i To all whom it may concern.'

Be it known that I, CHARLES MoCoRMIoK, a citizen of the United States, residing at Chicago, in the county of Cook and State of Illinois,have invented certain new and useful Improvements in Ophthalmoscopes, of which the following is a specification.

This invention relates to that type of ophthalmoscopes in which the indirect methodfof observing the eye of the patient is employed,

and has for its objects to dispense with the use of a mirror or reiiecting-surface for obtaining the observations, to employ a tube carrying iFigure 1 is a sectional elevation of the complete instrument with the several parts propat one end thereof an adjustable convex lens and having at its other end meanslfor producing the required degree of artificial light to make the observations, 'to construct anophthalmoscope in a very compact form, embodying therein a tube, an'fadjustable lens, lightproducing means, and a sight-tube and sightopening, and to improve generally the construction ,and operation of the Ophthalmoscopes as awhole.

The invention consists in the features of construction and combination of parts hereinafter described-and claimed. v

- In the' drawings illustrating the invention,

erly assembled for use; Fig. 2, an elevation of the adjustable sleeve carrying a convex lens at the patients end of the instrument; Fig. 3, a sectional elevation of the sleeve carrying the convex lens;v Fig. 4, an end elevation of the su pport for the lights and of the sight-tube surrounded by the lights; Fig. 5,

a side elevation of the support for the lights, and Fig. 6 a sectional elevation of the support with the lights in full elevation.

The ophthalmoscopic instrument ofthe invention is constructed with a main tube A of the length required, which tube for general use as to length can be twenty inches, or thereabout, and this tube at one end is open and has in its bodyy back of the open end a longitudinal slot a in the arrangement shown. The open end of the tube has located therein a sleeve B, carrying a convex lens b, which lens preferably is` set at an inclination, as shown in Figs. 1 and 3, thereby changing the focus or focal point ofthe lens in its relation to the body of the tube, so as to concentratethe rays centrally of the lens at an angle, though the lenscould beset perfectly vertical, if so desired. ,',Thesleeve B is adjustable in the tube A, and, as shown, for making the adjustments ya finger-piece having a stem extendingA through the slot a, 'is employed, by which the operator of the instrument can move the sleeve B and with it the lens toward and from the open end of the tube A to properly focus the lens with the eye of the patient for obtaining y.

the necessary conjugate focus to show the condition of theA eye. tube has entered` thereinto a support C,which support is open at its inner end and .is closed at its outer end by a header disk c, made :in two `halves or members, which are of a'greater The opposite endfofthel diameter than the diameter of the tube A, so

as to abut against the end of the tube and form a stop for the entrance of the support C into `the tube. The end head or disk has vattached thereto lighting means, which, as shown, is in the form of a series of small-candle-power incandescent lights D, six lights being shown;

but a greater or less number can be used, 'according to the size of the instrument and the required amount of light desired, and where incandescent lights are used such lights are connected with lead-wires or conductors d of an electric current, the conductors being entered between the two halves or members of the head or disk c, so as to be out of the way of the operator, the lead-wires or conductors being insulated and having connection with a suitable source of electricity, such as a dynamo or a line-wire leading from a sourceof electric supply or with some other source of electric energy, suchas Va battery,` suiiicient to'operate the incandescent lights.

The support has at the center thereof a sight-tube vE with an opening therethrough, and', as shown, at the outer end of the sighttube is an eyepiece e to inclose the eye of the operator, and .the casing and the sight-tube are of a greater length thanv the length 'of the incandescent lights in the arrangement shown. The tube A has therein at a point in advance of the inner end of the casing or support C frosted or ground glass F with Va sight-hole f of a less diameter than the diameter of the hole or opening in the sight-tube E, and this sight-hole f is centrally in line with the center of the convex lens so that the rays from the eye of the patient transmitted through the lens will be carried back through the sighthole f and the sight-tube E to the eye of the operator to enable the operator to discover the condition of the eye of the patient as to abnormal or mechanical defects in the eye and by moving the lens forward or backward, as may be required, obtain the requisite point for the true focus on the eye of the patient.

The operation is as follows: The operator, .placing his eye so as to be inclosed by the cap or closure e of the sight-tube, looks through the sight-tube and the opening or hole f and the lens into the eye of the patient at the open end of the tube A and through the medium of4 the light from the-incandescent lights or other direct lighting means and lthe lens b is'enabled to make careful and accurate observations as to the condition of the eye of the patient internally and externally. In order to prevent the rays of artificial light from interfering with the reflected rays from the eye of the patient, the ground glass or other similar means is placed between the artificial lighting means and the lens, so that the space between the lighting means and the lens will be dark as compared with the light back of the glass and the rays of light projected through 'the sight opening or hole f from the lens, thus insuring an observation of the eye of the patient under positive and accurate conditions as to reflected light, the rays of light from the eye of the patient making it possible to ascertain'the condition of the eye of the patient without the use of any mirror or other means for producing reflected light.

'Ihe instrument is simple in construction, but will be found positive and reliable in use, enabling direct illumination or 'light to 'be utilized without the employment of a mirror or other reflecting-surface in conjunction with a convex lens adjustable in relation to the eye of the patient and the sight-tube for the operator.

It is to be understood that in the use of the instrument such mechanicalchanges are tobe made as may be necessary to adapt the instrument in regard to the lens employed and the degree of artificial light required to suit the conditions of use, and such changes will not be a departure from the spirit of the invention, which is in dispensing with the use of a mirror or reflecting-surface in ophthalmoscopes and in employing direct illumination for making observations of the eye.

.What I regard as new, and desire to secure by Letters Patent, is-

1. In an ophthalmoscope, the combination of amain tube open at one end, a slidable sleeve within the main tube at its open end, a lens carried by the sliding sleeve, means for producing artificial light at the opposite end of and within the main tube, and a sight-tube within the circle of artificial lights, substantially as described.

2. In an ophthalmoscope, the combination of amain tube open at one end, a slidable sleeve within the main tube at its open end, a lens carried by the sliding sleeve,means for producing artificial light at the opposite end of and within the main tube, a sight-tube within the circle of artificial lights, means for preventing the projection of the rays of artificial light toward the lens-tube, said means having -therein a sight-hole forward of the sight-tube and rearward of the lens, substantially as described.

3. In an ophthalmoscope, the combinationv of a main tube open at one end, a slidable sleeve within the main tube at its open end, a lens carried by the sliding sleeve, a light-carrier at the opposite end of the main tube, incandescent electric lights mounted on the carrier within the circle of the main tube, and a sighttube within the circle of incandescent lights,

substantially as described.

4. In an ophthalmoscope, the combination of a main tube open at one end, a slidable sleeve within the main tube at its open end, a lens `carried by the sliding sleeve, a light-carrier at the opposite end of the main tube, incandescent electric lights mounted on the carrier, a sight-tube within the circle of incandescent lights, a frosted 'glass having at its center a sight-hole and located inthe main tube betweenthe lens and the sight-tube, substantially as described.

5. In an ophthalmoscope, the combination of a main tube, an adjustable lens at one end of the tube, and means for producing artificial light at the opposite end of and within the main tube, substantially as described` 6. In an ophthalmoscope, the combination of a main tube, an adjustable lens at one end of the tube, a'means for producing artificial light at the opposite end of and within the main tube, a sight-tube at the opposite end of the main tube t0 the adjustable lens, and a cross-partition located Within the main tube and having a sight-hole therein to coact with the sight-tube, substantially as described.

7. In an ophthalmoscope, the combination of a main tube, an adjustable convex lens at one end of the main tube, incandescent lights at the opposite end of and within the main tube, a sight-tube within the incandescent lights, and aA cross-partition located within the main tube forward of the sight-tube and having therein a sight-hole in central axial line with the sight-tube, substantially as described'.

8. In an ophthalmoscope, the combination of a main tube, an adjustable lens at one end of the tube and set inclined, a means for producing articial light at the opposite end of and within the main tube, a sight-tube at the opposite end of the main tube to the adjustable IOG IOS

of a main tube, 'an adjustable convex lens at one end of the main tube and set inclined, in-

candescent lights at the opposite end of and Within the main tube, a sight-tube Within the incandescent lights, and a cross-partition lo-V IO cated Within the main tube forward of the sight-tube and having therein a sight-hole in Central axial line therewith, substantially as.

described.

CHARLES MGCORMICK. Witnesses:

OSCAR W. BOND, PEARL ECKHARD. 

